U.S. patent application number 14/126889 was filed with the patent office on 2014-08-28 for system having a boundary conductor unit and an independent mobile unit.
This patent application is currently assigned to Robert Bosch GmbH. The applicant listed for this patent is Amos Albert, Christoph Koch, Steffen Petereit. Invention is credited to Amos Albert, Christoph Koch, Steffen Petereit.
Application Number | 20140242907 14/126889 |
Document ID | / |
Family ID | 46026801 |
Filed Date | 2014-08-28 |
United States Patent
Application |
20140242907 |
Kind Code |
A1 |
Petereit; Steffen ; et
al. |
August 28, 2014 |
System having a Boundary Conductor Unit and an Independent Mobile
Unit
Abstract
A system has a boundary conductor unit, which is intended to
emit a boundary signal, and an at least partially independent
mobile unit, which is intended to detect a boundary provided by the
boundary conductor unit by means of cross-correlation. It is
proposed that the mobile unit has at least one receiving unit which
is intended to receive data transmitted by means of the boundary
signal.
Inventors: |
Petereit; Steffen; (Freiberg
A.N., DE) ; Koch; Christoph; (Stuttgart, DE) ;
Albert; Amos; (Leonberg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Petereit; Steffen
Koch; Christoph
Albert; Amos |
Freiberg A.N.
Stuttgart
Leonberg |
|
DE
DE
DE |
|
|
Assignee: |
Robert Bosch GmbH
Stuttgart
DE
|
Family ID: |
46026801 |
Appl. No.: |
14/126889 |
Filed: |
April 26, 2012 |
PCT Filed: |
April 26, 2012 |
PCT NO: |
PCT/EP2012/057675 |
371 Date: |
April 7, 2014 |
Current U.S.
Class: |
455/41.1 |
Current CPC
Class: |
G05B 15/02 20130101;
H04B 5/0075 20130101 |
Class at
Publication: |
455/41.1 |
International
Class: |
H04B 5/00 20060101
H04B005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2011 |
DE |
10 2011 077 673.7 |
Claims
1. A system comprising: a boundary conductor unit configured to
emit a boundary signal; and an at least partially independent
mobile unit configured to detect a boundary provided by the
boundary conductor unit by means of a cross-correlation, wherein
the mobile unit includes at least one receiving unit configured to
receive a data transmission by means of the boundary signal.
2. The system as claimed in claim 1, wherein the boundary signal
emitted by the boundary conductor unit is a pseudorandom
signal.
3. The system as claimed in claim 1, wherein the boundary conductor
unit includes at least one boundary conductor, which forms at least
one conductor loop.
4. The system as claimed in claim 1, wherein the at least one
receiving unit is configured to detect an inductive component of
the boundary signal.
5. The system as claimed in claim 1, wherein the mobile unit
includes a computing unit configured to evaluate the boundary
signal by means of a cross-correlation with a correlation bit
pattern.
6. The system as claimed in claim 5, wherein the computer unit
configured to generate at least two different correlation bit
patterns for the cross-correlation.
7. The system as claimed in claim 6, wherein: the at least two
correlation bit patterns includes a first correlation bit pattern
and a second correlation bit pattern, and the computing unit is
configured to allocate an operating mode to the first correlation
bit pattern and a command to the second correlation bit
pattern.
8. The system as claimed in claim 5, wherein the computing unit is
configured to detect a command transmitted by at least two
different phase angles of the correlation bit pattern of the
boundary signal.
9. An at least partially independent mobile unit of a system having
a boundary conductor unit, the mobile unit comprising: at least one
receiving unit configured to receive a data transmission by means
of a boundary signal emitted by the boundary conductor unit,
wherein the mobile unit is configured to detect a boundary provided
by the boundary conductor unit by means of a cross-correlation.
10. A boundary conductor unit of a system as claimed in claim
1.
11. A method comprising: emitting a boundary signal with at least
one boundary conductor unit during an operation; detecting a
boundary provided by the boundary conductor unit with an at least
partially independent mobile unit by means of a cross-correlation;
and transmitting data between the boundary conductor unit and the
mobile unit by means of the boundary signal.
Description
PRIOR ART
[0001] A system having a boundary conductor unit has already been
proposed which is provided for emitting a boundary signal, and
having an at least partially independent mobile unit which is
provided for detecting a boundary by the boundary conductor unit by
means of the boundary signal.
DISCLOSURE OF THE INVENTION
[0002] The invention is based on a system having a boundary
conductor unit which is provided for emitting a boundary signal,
and having an at least partially independent mobile unit which is
provided for detecting a boundary provided by the boundary
conductor unit by means of a cross-correlation.
[0003] It is proposed that the mobile unit has at least one
receiving unit which is provided for receiving a data transmission
by means of the boundary signal. A "boundary conductor unit" is
intended to be especially a unit which limits an area on at least
one side by means of a spatial extent of an electrical conductor. A
boundary conductor preferably conducts an electrical current which
is modulated with the boundary signal. The electrical current
advantageously causes a magnetic field modulated with the boundary
signal in the area limited by the boundary conductor unit.
"Provided" is intended to be understood particularly as specially
programmed, designed and/or equipped. In particular, a "boundary
signal" is intended to be understood to be a signal which has at
least one characteristic which differs within the limited area and
outside the limited area. The boundary signal can be received
preferably during an operation within a limited area. The boundary
signal is preferably designed as a binary signal. The boundary
signal preferably has at least one characteristic provided, in
particular, only for correlation. By itself, this characteristic is
not used for data transmission. A "binary signal" is intended to be
understood especially to be a signal which has an information item
composed exactly of two different information states. The boundary
signal preferably has a periodically repetitive binary sequence.
The term "emitting" is to be understood, in particular, to mean
that the boundary conductor unit emits a power of the boundary
signal into a space surrounding the boundary conductor unit. In
particular, "partially independent" is intended to be understood in
this context to mean that the mobile unit determines at least one
procedure on the basis of information which it has collected
itself. In particular, the mobile unit determines on the basis of
an information item a procedure which depends on a movement
relative to the boundary conductor unit, especially on reaching the
boundary. The mobile unit preferably determines at least one
characteristic variable of a path which it travels. For example,
the mobile unit could turn around when reaching the boundary.
"Mobile" is intended to be understood in this context to mean that
the unit moves relative to the boundary conductor unit in at least
one period of time. The unit preferably comprises a drive unit
which is provided for moving along the mobile unit relative to the
boundary conductor unit. The mobile unit advantageously comprises a
coupling means for coupling, which is, in particular, detachable by
an operator, to a mobile object and/or advantageously to an animal.
In particular, a "unit" is intended to be understood as a mobile
unit appearing to be appropriate to the expert which moves freely
in at least one state within a provided area limited by the
boundary conductor unit on at least one side. The unit preferably
handles a task during operation within the area. Alternatively or
additionally, the mobile unit could be provided for counteracting a
movement of an object and/or advantageously of an animal out of the
area limited by the boundary conductor unit. For example, the unit
could be designed as a lawn mowing robot, as a polishing robot
and/or as another unit appearing to be appropriate to the
expert.
[0004] Alternatively, the unit could be designed, for example, as a
collar for a dog and/or a cat. The mobile unit preferably has a
cableless power supply, especially a battery. A "boundary" is
intended to be understood in particular, as a plane which closes an
area, in which the mobile unit moves during an operation, on at
least one side. The boundary advantageously encloses an area around
360 degrees. A "cross-correlation" is intended to be understood in
particular, as a comparison of two signals for similarity, the
signals being displaced in time with respect to one another. In
particular, the term "to detect" is intended to be understood to
mean that the independent mobile unit receives the boundary signal
and determines by an evaluation of the boundary signal a
characteristic variable which signals at least one transgression of
the boundary during the transgression. A "receiving unit" is
intended to be understood to be a unit which is provided for
receiving a power radiated by the boundary conductor unit. The
receiving unit advantageously has at least one coil which receives
the power radiated by the boundary conductor unit during an
operation. In particular, a "data transmission" is intended to be
understood to be a transmission of at least one information item by
the boundary conductor unit to the mobile unit and/or especially
from the mobile unit to the boundary conductor unit. In particular,
the boundary conductor unit varies the boundary signal for data
transmission.
[0005] For example, the boundary conductor unit could modulate the
boundary signal in analogue and/or digital frequency, amplitude
and/or phase. Due to the embodiment according to the invention of
the system, a particularly interference-proof boundary can be
achieved with a constructionally simple and also particularly
interference-proof data transmission.
[0006] In a further embodiment, it is proposed that the boundary
conductor unit is provided for emitting the boundary signal which
is designed as a pseudorandom signal as a result of a which a low
sensitivity to interference with respect to narrow-band
interference can be achieved. In particular, a "pseudorandom
signal" is intended to be a signal which has an autocorrelation
with a major peak which is at least twice as large, preferably at
least four times as large as possibly present secondary peaks of
the autocorrelation. The boundary signal has preferably a
statistical characteristic of white noise. The boundary signal has
preferably a binary bit pattern. In particular, the boundary signal
is designed as a boundary signal appearing to the appropriate to
the expert, preferably however as a JPL sequence and/or
particularly preferred as a gold sequence.
[0007] It is also proposed that the boundary conductor unit has at
least one boundary conductor which forms at least one conductor
loop, as a result of which inductive data transmission and a
reliable boundary are possible in a structurally simple manner. In
particular, a "boundary conductor" is intended to be understood as
an electrically conductive cable which runs along the boundary. A
"conductor loop" is intended to be understood as an electrically
conductive cable which encloses an area. The boundary conductor is
preferably provided for enclosing an area greater than 5 m.sup.2,
particularly advantageously greater than 20 m.sup.2.
[0008] The enclosed area preferably forms the area limited by the
boundary conductor unit. In this context, the boundary conductor is
advantageously inserted a few centimeters into a bottom of the
limited area. Alternatively or additionally, the boundary conductor
could rest on the floor and, particularly, be grown into a green
covering the floor.
[0009] Furthermore, it is proposed that the receiving unit is
provided for detecting an inductive component of the boundary
signal as a result of which a particularly small antenna can be
used, especially a coil. In particular, the receiving unit has an
antenna, preferably a number of antennae. An "inductive component"
is intended to be understood in particular to mean that the
receiving unit is provided for receiving an inductive field and/or
an inactive component of an electromagnetic field. The receiving
unit is arranged preferably in a near field of the boundary
conductor unit during an operation. A "near field" is intended to
be understood in particular as a field at a distance from a
transmitter of the field which is smaller than twice a medium
wavelength of the field.
[0010] It is also proposed that the mobile unit has a computing
unit which is provided for evaluating the boundary signal by means
of a cross-correlation with a correlation bit pattern as a result
of which a particularly low influence of disturbances on an
evaluation of the reception can be achieved. A "computing unit" is
intended to be understood, in particular, as a unit having an
information input, information processing and an information
output. The computing unit has advantageously at least one
processor, one memory, input and output means, further electrical
components, an operating program, regulating routines, control
routines and/or calculation routines.
[0011] The components of the computing unit are arranged preferably
on a common board and/or arranged advantageously in a common
housing. In particular, a "correlation bit pattern" is intended to
be understood as a sequence of bits which is equal to a bit pattern
transmitted in at least one operating state by the boundary signal.
The computing unit is provided preferably for generating and/or
storing the correlation bit pattern. "Evaluating" is intended to be
understood, in particular, to mean that the computing unit
determines from at least one characteristic of the boundary signal
at least one information item about a site relative to the boundary
conductor unit.
[0012] It is also proposed that the computing unit is provided for
generating at least two different correlation bit patterns for the
cross-correlation as a result of which a data transmission and/or
simultaneous use of a number of systems in spatial vicinity is/are
possible in a structurally simple manner. In particular, a data
transmission without synchronization to a clock transmitted with
the boundary signal is possible. Furthermore, it can be prevented
in a structurally simple manner that a command does not reach the
mobile unit due to a time-limited disturbance as a result of which
a return channel can be advantageously omitted. In particular,
"different correlation bit patterns" are intended to be understood
to be bit patterns which are at least essentially orthogonal to one
another. This means, in particular, that during a correlation two
identical bit patterns, a major peak of a result is at least twice
as large, advantageously 4 times as large as in a correlation of
two orthogonal bit patterns. The computing unit is preferably
provided for correlating a received boundary signal with a first
correlation bit pattern and/or with a second correlation bit
pattern during an operation. In particular, the computing unit is
provided for correlating a time interval of the boundary signal
with the first correlation bit pattern and the second correlation
bit pattern. Alternatively, the computing unit is provided for
correlating a first time interval of the boundary signal with the
first correlation bit pattern and a second time interval of the
boundary signal with the second correlation bit pattern.
[0013] In an advantageous embodiment of the invention, it is
proposed that the computing unit allocates an operating mode to the
first correlation bit pattern and a command to the second
correlation bit pattern as a result of which a particularly simple
implementation can be achieved. An "operating mode" is intended to
be understood in particular as an operating state of the mobile
unit in which the unit handles a task, for example lawn mowing,
polishing or monitoring a site. In particular, a "command" is
intended to be understood as a data transmission which influences a
behavior of the mobile unit. The command advantageously causes a
reaction, appearing to be appropriate to the expert, of the mobile
unit, for example approaching a particular point, emergency stop
and/or coming to eat food. The correlation bit pattern to which a
command is allocated is transmitted preferably during an entire
execution of the command. Alternatively, the correlation bit
pattern, which is allocated to a command, could be emitted up to a
confirmation and/or for an intended period of time.
[0014] Furthermore, it is proposed that the computing unit is
provided for detecting a command transmitted by at least two
different phase angles of a bit pattern of the boundary signal by
which means a high data transmission rate is possible in a
structurally simple manner. A "phase angle" is intended to be
understood to be, in particular, that the boundary conductor unit
displaces a time of an emission of a particular bit of the bit
pattern within a period with respect to a previous period of the
bit pattern.
[0015] The invention is also based on an independent mobile unit of
a system according to the invention.
[0016] Furthermore, the invention is based on a boundary conductor
unit of a system according to the invention.
[0017] In addition, the invention is based on a method having at
least one boundary conductor unit which emits a boundary signal
during an operation, and having an at least partially independent
mobile unit which detects a boundary provided by the boundary
conductor unit by means of a cross-correlation.
[0018] A data transmission is proposed between the boundary
conductor unit and the mobile unit by means of the boundary
signal.
DRAWING
[0019] Further advantages are obtained from the description of the
following drawing. In the drawing, two exemplary embodiments of the
invention are shown. The drawing, the description and the claims
contain numerous features in combination. The expert will also
suitably consider the features individually and combine them to
form appropriate further combinations.
[0020] In the drawings:
[0021] FIG. 1 shows a system according to the invention having a
boundary conductor unit and a mobile unit,
[0022] FIG. 2 shows a boundary signal received by the mobile unit
and a scanning of the boundary signal,
[0023] FIG. 3 shows results of a cross-correlation of the received
boundary signal with correlation bit patterns of a first and a
second exemplary embodiment,
[0024] FIG. 4 shows a flow chart of an operation and of a data
transmission of the system from FIG. 1 of the first exemplary
embodiment.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0025] FIG. 1 shows a system 10 having a boundary conductor unit 12
and an independent mobile unit 16. The boundary conductor unit 12
comprises a boundary conductor 20 and a base station 28. The base
station 28 has an input unit 30 and a signal generator 32. The
signal generator couples a boundary signal 14 to the boundary
conductor 20 during an operation. The boundary signal is designed
as a pseudorandom signal. For this purpose, the signal generator 32
has a code generator, not shown in greater detail, which is
provided for generating gold sequences. The boundary conductor 20
forms a conductor loop which encloses an area 34. Coupling the
boundary signal 14 into the boundary conductor 20 causes an
electrical current in the boundary conductor 20. The electrical
current causes a magnetic field 36 in the area 34 within the
boundary signal 14 and a magnetic field 38 outside the conductor
loop of the boundary conductor 20. The magnetic fields 36, 38 have
opposite directions relative to a plane spanned by the area 34.
[0026] The mobile unit 16 is formed as an independent lawnmower.
The mobile unit 16 mows the area limited by the boundary conductor
20 independently during an operation. The mobile unit 16 has a
receiving unit 18 and a drive unit 40. The drive unit 40 moves the
mobile unit during an operation. The receiving unit 18 has a
computing unit 22 and an antenna 42. The antenna 42 is constructed
as a coil. The antenna 42 of the receiving unit 18 thus detecting
an inductive component of the boundary signal 14. The computing
unit 22 is constructed as a microcontroller. It comprises a
correlation calculating routine which is provided for performing a
cross-correlation between a correlation bit pattern and the
received boundary signal 14 in an operational state. For this
purpose, the computing unit 22 has a code generator, not shown in
greater detail here, which is provided for generating gold
sequences.
[0027] The code generator of the computing unit 22 generates an
identical code as the code generator of the boundary conductor unit
12 in at least one operating state.
[0028] The computing unit 22 has an analogue/digital converter, not
shown in greater detail, which digitizes the received boundary
signal 14 with a sampling period 44 as shown in FIG. 2. The
received boundary signal shown has disturbances. The sampling
period 44 of the analogue/digital converter is shorter than a
period of one bit of the boundary signal 14. The computing unit 22
correlates periodically a time interval 46 of the boundary signal
14 with the generated correlation bit pattern which is equal to a
bit pattern of the boundary signal 14. Possible results of the
correlation are shown in FIG. 3 without possible disturbances. The
results have in each case a positive or negative peak 48, 50, 52
when the receiving unit receives the boundary signal 14 and the bit
pattern of the boundary signal 14 and the correlation bit pattern
match. When the mobile unit is arranged within the limited area 34,
the results of the periodically repeated correlation have in each
case a negative peak 48. When the mobile unit 16 has left the
limited area 34, the results of the periodically repeated
correlation in this incident have in each case a positive peak 50
because the magnetic fields 36, 38 received by the receiving unit
18 have different directions within and outside of the area 34.
[0029] The input unit 30 has an operating element, not shown in
greater detail, by means of which the operator can issue a command
to the mobile unit 16. To transmit the command, the signal
generator 32 changes the emitted boundary signal 14. The boundary
signal 14 thus has data which are allocated to the command during
the transmission of the command. The receiving unit 18 of the
mobile unit 16 evaluates the boundary signal 14 and thus receives
the data transmission through the boundary signal 14.
[0030] In a first exemplary embodiment, the signal generator of the
boundary conductor unit 12 generates different bit patterns for the
data transmission. The bit patterns are allocated to different
commands and/or operating states. The computing unit 22 of the
mobile unit 16 generates different correlation bit patterns for the
cross-correlation during an operation. In FIG. 4, a possible
operating sequence is shown.
[0031] After an initialization 54, the computing unit 22 begins a
search 56 for an operating bit pattern by means of the correlation
with an operating bit pattern. In this context, the computing unit
22 stops the mobile unit 16 via the drive unit 40. When the
computing unit 22 has found 58 the operating bit pattern, the
mobile unit 16 begins to work 60. In this context, the computing
unit 22 continues to correlate the received signal with the
operating bit pattern. When the computing unit 22 no longer finds
62 the operating bit pattern in the received signal, the computing
unit 22 stops the mobile unit 16. The computing unit 22 begins the
search 56 for the operating bit pattern again.
[0032] When the computing unit 22 does not find 62 the operating
bit pattern, the computing unit 22 checks whether a maximum search
period provided has elapsed 64. When the maximum search period has
not elapsed 66, the computing unit 22 continues to search 56 for
the operating bit pattern in the boundary signal 14. When the
maximum search period for the operating bit pattern, in this case
for example one second, has elapsed 68, the computing unit 22
searches 70, by means of the correlation with a command bit
pattern, for a further command, for example for a return command.
During the search of the command bit pattern, the mobile unit 16 is
stopped.
[0033] When the computing unit 22 has found 72 the command bit
pattern, the mobile unit 16 executes the command 74. When the
computing unit 22 does not find 76 the command bit pattern, the
computing unit 22 checks whether a maximum search period provided
has elapsed 78. When the maximum search period for the command bit
pattern has elapsed 80, the computing unit 22 here searches 56
again for the operating bit pattern. Alternatively, the computing
unit 22 could initially search for a further command bit pattern or
a number of further command bit patterns in accordance with the
same principle.
[0034] The input unit 30 of the boundary conductor unit 12 has an
operating element, not represented in greater detail, which
interrupts an emission of the operating bit pattern as a result of
which stopping and/or pausing the mobile unit 16 is possible in a
constructionally simple manner. Furthermore, the input unit 30 of
the boundary conductor unit 12 has an operating element, not shown
in greater detail, by means of which the operator can select the
operating bit pattern from an operation. Alternatively, an
operating bit pattern could be preset ex-factory in a boundary
conductor unit and a mobile unit. In a further alternative, a
boundary conductor unit could independently select an operating bit
pattern, especially randomly and/or in that the boundary conductor
unit searches in a signal captured by the boundary conductor for
any operating bit patterns occupied by other systems.
[0035] The mobile unit 16 detects the operating bit pattern during
a commissioning in that it searches a set of bit patterns for the
bit pattern emitted by the boundary conductor unit. Alternatively,
an operator could input the operating bit pattern manually into a
mobile unit. The command bit patterns are selected depending on the
operating bit pattern. Alternatively, each selected bit pattern
deviating from the operating bit pattern could be allocated to an
identical command, especially to a return command.
[0036] In an alternative exemplary embodiment, a computing unit 22
of a mobile unit 16 of a system 10 could acquire a command which is
transmitted by two different phase angles 24, 26 of an individual
bit pattern of a boundary signal 14. The phase angles 24, 26 of the
boundary signal 14 are apparent in a result of a correlation due to
a different arrangement of the peaks 48, 52. The computing unit 22
correlates the received boundary signal 14 with a correlation bit
pattern which corresponds to the bit pattern of the boundary signal
14. The computing unit 22 here correlates time intervals of the
boundary signal 14 periodically with a correlation bit pattern
which correspond to a period of the bit pattern of the boundary
signal 14. A boundary conductor unit 12 of the system 10 varies a
phase angle of the bit pattern of the boundary signal 14. As shown
in FIG. 3, this displaces a position of a peak of a result of the
correlation. The boundary signal 14 transmits data to the mobile
unit 16 by this means.
* * * * *